Best Overall Pair of Long Underwear
SmartWool NTS Mid 250
Warm for the weight
Dries relatively slowly
After all the blood, sweat, and testing, we were able to choose one clear winner, merino wool, and specifically, the Smartwool NTS Mid 250
. Merino wool's advantages over synthetics in warmth and breathability make it our favorite long underwear fabric, and the NTS 250's stylish construction and attention to detail bring it out on top. We particularly like the slim-fit waist (which helps it stay down when active), the gentle stretch of its 250 g/m² wool, and the overall comfort and fit. This model delivers in cold temperatures as our first of multiple layers, as well as on its own in warmer conditions. When switching between tops during testing, it was very clear than pulling this product over our torsos led to the most pleasure and performance. While some products were better suited for a particular use, if we could only have one base layer, the NTS Mid 250 would be it.
Best Bang for the Buck
The North Face Warm
Solid all around
Not very warm
Average drying speed
Looking at some of the prices in the base layer marketplace, you might be wondering if it's possible to purchase an effective base layer that doesn't break the bank. The answer lies in The North Face Warm
. From the moment we slipped into this smooth operator, we were impressed by its great comfort. It doesn't itch at all, but rather caresses your torso. It's quite capable when layering over and under this model, and breathes sufficiently, too. We were also psyched on this product's durability, with bomber seams and solid synthetic fabric. It didn't regulate temperature as well as some of the merino wool and blended fabric products, but we still found it suitable to a range of activities and temperatures. For exceptional value in a base layer that is built to last several seasons, we recommend our Best Buy award winner, the Warm from The North Face.
Top Pick for Lightweight
Rab Merino+ 160
Fastest drying model
Not very warm
In our field of competitors, there wasn't a lightweight model that performed nearly as well as the Rab Merino+ 160
, which only weighs 7.5 oz. This product of blended merino wool and polyester rocked the boat in several categories, giving new inspiration to what thinner, lighter base layers are capable of. It has an excellent fit, feels great, layers surprisingly well, and breathes like a mechanical lung. Most impressively, this was the fastest-drying fabric in the group of competitors. Being so thin, it didn't provide much durability or warmth. Our reviewers and friends also agreed that this model is good to go for social environments as well. However, if you're looking for the best combination of performance and lightweightedness for use in mostly cool temperatures, or cold weather as a first layer, our Top Pick for Lightweight award winner offers just that.